Cardiogenic shock (CS) is defined as persistent hypotension (systolic blood pressure <90 mmHg for >30 minutes, or the need for vasopressors or inotropes), end-organ hypo-perfusion (urine output <30 mL/h, cool extremities or lactate > 2 mmol/L), pulmonary congestion (pulmonary capillary wedge pressure (PCWP) ≥ 15 mmHg) and decrease cardiac performance (cardiac index <2.2
)1,2 due to a primary cardiac disorder. Acute myocardial infarction (AMI) is the most common cause of CS3. CS occurs in 5-10% of AMI and historically has been associated with significant mortality3,4. Mechanical circulatory support (MCS) devices such as intra-aortic balloon pump (IABP), percutaneous ventricular assist devices (PVAD), extracorporeal membrane oxygenation (ECMO) and percutaneous left atrial to aortic devices are frequently used in patients with CS5. Routine use of IABP has demonstrated no improvement in clinical outcomes or survival in AMI-CS1. Given the poor outcomes associated with AMI-CS, the difficulties in conducting trials in AMI-CS, and the negative results of IABP use in AMI-CS, clinicians are increasingly looking to other forms of MCS.
PVADs are increasingly utilized in patients with AMI-CS6. In this article, we will focus our discussion primarily on the Impella CP, which is the most common PVAD used currently6. This device utilizes an axial flow Archimedes-screw pump which actively and continuously propels blood from the left ventricle (LV) into the ascending aorta (Figure 1). The device is most frequently placed in the cardiac catheterization laboratory under fluoroscopic guidance via the femoral artery. Alternatively, it can be implanted through an axillary or transcaval access when necessary7,8.